Examine source code of Browser Time Machine

{
  "manifest_version": 3,
  "name": "Time Machine",
  "description": "__MSG_extensionDescription__",
  "version": "2.0.0",
  "default_locale": "en",
  "minimum_chrome_version": "109",
  "icons": {
    "16": "images/icon-16.png",
    "32": "images/icon-32.png",
    "48": "images/icon-48.png",
    "128": "images/icon-128.png"
  },
  "background": {
    "type": "module",
    "scripts": [
      "scripts/worker.js"
    ]
  },
  "action": {
    "default_icon": {
      "16": "images/icon-16.png",
      "32": "images/icon-32.png",
      "48": "images/icon-48.png",
      "128": "images/icon-128.png"
    },
    "default_popup": "popup/main.html",
    "default_area": "navbar"
  },
  "permissions": [
    "activeTab",
    "scripting"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{9add32c7-2792-40ed-a676-5605bf24d3d2}",
      "strict_min_version": "128.0"
    },
    "gecko_android": {
      "id": "{9add32c7-2792-40ed-a676-5605bf24d3d2}",
      "strict_min_version": "128.0"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*",
        "file://*/*"
      ],
      "js": [
        "scripts/replace_date.js"
      ],
      "all_frames": true,
      "match_about_blank": true,
      "run_at": "document_start",
      "world": "MAIN"
    }
  ]
}